Known as an example of such a vehicle door opening-closing apparatus is a vehicle door opening-closing apparatus operating in cooperation with a locking system (smart entry system) for automatically controlling unlocking and locking of a vehicle door. The smart entry system detects the user approaching the vehicle or getting off by communicating with a mobile device carried by the user, recognizes a user's unlocking or locking command for the vehicle door, and controls locking or unlocking the vehicle door. Japanese Patent Laid Open No. 2002-295064 discloses a vehicle door opening-closing apparatus in such a smart entry system. In the vehicle door opening-closing apparatus, a detection electrode is provided for a door handle for which the user performs vehicle door opening or closing operation (refer to paragraphs 2 to 9). The vehicle door opening-closing apparatus uses an electrostatic capacity formed between the detection electrode and the vehicle door to detect a change in the electrostatic capacity caused by inserting a hand of the user between the detection electrode and the vehicle door, and recognizes a command of the user.
Japanese Patent Laid Open No. 2005-98016 (refer to paragraphs 90 to 101, FIG. 20, etc.,) discloses a vehicle door opening-closing apparatus for checking the personal identification number as the user grips a door handle and unlocks the door or produces a vibration rhythm by striking the door.
In the vehicle door opening-closing apparatus for detecting a change in the electrostatic capacity between the detection electrode provided for the door handle and the vehicle door in the related art, however, the electrostatic capacity changes if a substance different from the air in medium constant exists between the detection electrode and the vehicle door although the substance is other than a hand of the user. Thus, a change in the electrostatic capacity may also be detected as the environment of rain, etc., changes; the door may be opened regardless of user's intention because of malfunction in a system for automatically performing operation from unlocking to full opening of the door. To open the door, the user always needs to insert a hand into the door handle or operate a remote key; however, if both hands of the user are full, it is difficult to perform door opening or closing operation, and improvement of the operability is demanded.
To open or close the door by rhythmical striking, vibration propagates to the whole vehicle and thus a door for which the user does not perform opening or closing operation is not performed may be opened or closed because of malfunction. There is also a possibility that a door for which the user does not perform opening or closing operation may be opened or closed because of vibration of rain, hail, etc.